In a SAGD processes, steam is injected into a formation along the entire length of an injection well. This often results in an unpredictable and unequal propagation of the steam chamber around the entire length of the injection well. For example, steam heat may propagate excessively at the toe and/or heel sections of the injection well, with little propagation at the middle regions. The steam chamber, in general, tends to propagate through regions of the formation where there is the least resistance to flow, and usually does not propagate consistently and uniformly around the injection well. As a result, there may be regions in the formation that are not adequately extracted from. Thus, there is room for improvement in the SAGD art.